Generally speaking, a typical automotive axle assembly consists of a housing, gear set, differential, a pair of axle shafts, and supporting ancillary components. In simple terms, rotational effort is input through a pinion gear which turns a ring gear. The ring gear is fastened to a differential which then directs torque to the two axles. The job of the differential is to allow a variation in axle speed as the vehicle travels around corners.
In many racing environments, there are several drawbacks to using a differential including undesirable weight, insufficient strength, and less than optimal ability to deliver torque to the axles through varying traction conditions. For these reasons, a device called a spool may be employed. A typical spool is a one-piece component (see FIGS. 1 and 2) that engages both rear axles (driver and passenger side) effectively locking them together. This means both axles will rotate at the same rate regardless of vehicle dynamics and available traction. The end result is the ability to transfer more torque through the axles improving tractive effort. Also, the simple design of the current one-piece spool reduces weight over a standard differential. In addition, the improved material of the current one-piece spool yields enhanced strength.
However, the desire and benefits to reducing weight in automobile components, especially racing automobile components is always present. In addition, the desire and benefits to providing stronger and more reliable automobile components, especially racing automobile components is also always present. As such, there is clearly an unmet need to provide a spool for the axle assembly of an automobile that is lighter in weight, stronger, and/or more reliable or lasts longer than the conventional one-piece component.
The instant disclosure of a multiple-piece spool may be designed to address at least some aspects of the problems disclosed above.